Vinyl asbestos composition stabilized with melamine and rosin



United States Patent 3,314,906 VINYL ASBESTOS COMPOSITION STABILIZED WllTH MELAMINE AND ROSIN George E. Bagley, Lancaster County, Pa. (2425 Mayfair Drive, Lancaster, Pa. 17603), and William F. Goodyear, In, Lancaster County, Pa. (72 Barre Drive, Lancaster, Pa. 17601) No Drawing. Filed Feb. 26, 1965, Ser. No. 435,721

8 Claims. (Cl. 260-27) This invention relates generally to a Vinyl asbestos composition, and more particularly to a vinyl asbestos composition for use in the formation of flooring tile. Still more particularly, the invention relates to vinyl asbestos composition tile which is resistant to the effects of heat and moisture when installed as a floor.

Tiles containing vinyl halide resins and asbestos are subject to discoloration and to moisture .pickup when in use. Heat may cause discoloration of the tile and moisture, if it is absorbed, may cause growth of the tile with attendant buckling or other destruction of the floor.

US. Patent No. 3,084,135, Scullin, issued Apr. 2, 1963, discloses a vinyl asbestos composition stabilized with a heat-stabilizing amount of melamine. The disclosure of that patent is hereby incorporated herein by reference. The addition of melamine to a vinyl asbestos tile composition produces many advantages in the tile composition. However, one problem remains. The use of different asbestoses in the vinyl asbestos composition in conjunction with the melamine Will often produce a tile which has a pink color. This pink color may disappear on exposure to light or air or both as far as the surface appearance is concerned, but when the surface is removed, it is found that the pink color extends all the way through the tile. Although it has been found that certain compounds, for example bisphenols and polyhydroxyl compounds such as pentaerythritol, may eliminate the pink color from the melamine-containing vinyl asbestos composition, such compounds are water sensitive. To the extent that they are water sensitive, they are undesirable in the vinyl asbestos composition. Furthermore, these compounds are difficult to incorporate into the tile-making process. Hence there is a need for an additive to eliminate these difliculties.

It is the primary object of the present invention to supply such an additive. It is a further object of the present invention to supply a vinyl asbestos tile composition which is stable to heat and to moist conditions. It is still another object of the present invention to present a stable vinyl asbestos composition suitable for making heat and moisture-resistant tile economically by existing methods of tile manufacture.

These objects are achieved in a strikingly straightforward and eifective manner. The invention contemplates a vinyl asbestos composition comprising a vinyl chloride resin, asbestos, and a stabilizing system comprising a stabilizng amount of melamine and rosin acid.

The vinyl chloride resins used in the composition of the present invention are the addition polymers produced by polymerization of vinyl chloride either alone or in the presence of one or more polymerizable compounds. Preferably the vinyl chloride resin will be a straight poly- (vinyl chloride), or a vinyl chloride-vinyl acetate copolymer, or a mixture of the two types of resins. The

3,314,906 Patented Apr. 18, 1967 vinyl acetate copolymers contain generally about 3% up to about 20% by weight vinyl acetate copolymerized with the vinyl chloride, and most preferably, about 13% by weight vinyl acetate. These resins will generally have an intrinsicviscosity in cyclohexanone at a temperature of 30 C. of between about 0.3 and 1. The vinyl chloride may also be copolymerized with such comonomers as vinylidene chloride, vinyl proprionate, vinyl butyrate, or the acrylates or methacrylates. The vinyl chloride resin serving as a binder will generally be present in the vinyl asbestos composition in an amount of about 8%-30% by weight of the total composition.

Accompanying the vinyl chloride resin binder will be any of the plasticizers suitable for plasticizing the vinyl chloride resin. Such plasticizers are well known and may be any of such standard plasticizers as tricresyl phosphate, dibutyl phthalate, dioctyl phthalate, butyl benzylphthalate, butyl octyl phthalate, dipropylene glycol dibenzoate, and the epoxidized vegetable oils such as epoxidized soya bean oil. This last plasticizer also has a stabilizing effect against degradation of the vinyl chloride resin through the action of heat or light. Polyester plasticizers for the vinyl chloride resins may also be used. Generally speaking, such plasticizers will be present in an amount of about 0.2%10% by weight plasticizer based on the weight of the total composition.

The vinyl asbestos compositions contain a fibrous filler in the form of asbestos, preferably chrysotile asbestos. Long asbestos fibers are unnecessary, and economy normally dictates the use of the shorter fiber lengths such as 7D, 7R, and other similar short fibers. While long fibers may be introduced into the: composition, they will generally be shortened during the thorough mixing processes that must be undertaken to blend the ingredients in the composition. The amount of asbestos to be used will generally be in the range of about 3%50% by Weight asbestos based on the weight of the total composition.

Vinyl asbestos compositions also contain a granular inorganic filler, preferably ground limestone. However, in place of the calcium carbonate there may be used calcium silicate, barium sulfate, barium carbonate, silicon dioxide, ground serpentine, magnesium silicate, the tales, and other granular, inert, inorganic materials. The size range for the granular or powdered inorganic fillers will generally be between 20 mesh and 200 mesh, U.S. series, preferably about 40 mesh, with minor fractions of the filler permissibly being even smaller than 200 mesh. The granular inorganic filler is generally present in the vinyl asbestos composition in an amount of 20%80% by weight based on the weight of the total composition.

The vinyl asbestos composition will also generally contain relatively small amounts of pigments such as titanium dioxide or other coloring agents to impart the desired appearance to the tile composition. Small amounts of additional materials such as hydrocarbon resins, lubricants, additional stabilizers, such as the zinc, barium and cadmium salts of organic acids such as lauric and stearic may also be incorporated. Such pigments, lubricants, coloring agents, and other additives, will generally be present in an amount less than about 10% by weight of the total composition.

The melamine to be added to the vinyl asbestos composition is a known item of commerce. The addition of nelamine does a good job of stabilizing the vinyl as- )estos tile composition against the degradative effects of ieat and light on the tile when installed on the floor. The nelarnine also has some beneficial effects in minimizing cule of a carboxylic acid group. The dimer rosin acid has two such groups since the acid groups survive the polymerization intact. It is postulated that the acid group of the rosin acid reacts with the asbestos fiber in noisture pickup of the tile. However, as mentioned 5 the vinyl asbestos tile composition and thus has some earlier, an unacceptable pink color often appears in the effect on the iron in the asbestos composition, serving to Lile made from a vinyl asbestos composition containing eliminate the coloring effect of the iron. The dimer rosin nelamine. To make an acceptable tile, this pink color acid performs slightly better than the rosin acid itself, must be eliminated. At the same time, it is desirable to possibly because of the presence of two carboxylic acid enhance the effect of the melamine in minimizing moisgroups on the single larger molecule. The use of a com- :ure pickup by the finished tile. In the above-identified mercial rosin, containing as it does a heterogeneous mix- Scullin patent, it is stated that the vinyl asbestos comture of rosin acids, produces approximately the same reposition should contain approximately 0.3 to 10 and prefsult in the present invention as does pure abietic acid erably 1 to 5 parts by weight of the melamine per 100 itself. The rosin acid is to be used in the present comparts by weight of the vinyl chloride resin. Put on anposition in an amount in the range of about 0.05 %-4% by other basis for the purposes of the present invention, the weight based on the total weight of the composition. vinyl asbestos composition should contain 0.1%2.5% Preferably, the amount will be in the range of about by weight melamine based on the total weight of the 0.2%-1.2% by weight.

composition, and preferably about 0.4%1%. It should be emphasized that those rosin acid derivatives The particular additive of the present invention which which do not contain a carboxylic acid group do not give solves the problems left by the use of melamine alone or the unexpectedly good results of the rosin acids themrnelamine in combination with other known additives is selves. Compositions containing rosin acid esters do not rosin acid. The term rosin acid is used herein to idenproduce satisfactory results. tify the acids found in any of the commercial rosins. In forming the vinyl asbestos composition tile, all the Commercial rosin is of three types, gum rosin, wood ingredients are thoroughly blended at a temperature genrosin, and rosin obtained from tall oil. Gum rosin is the lly in the range of 250350 F. Mixing Will often residue of a distillation performed on a sticky mixture k 45 Seconds to i minutes i a B b mixer d called oleoresin Obtained from a ppe living p tree- 15 to 45 minutes at the elevated temperature in a Baker- Wood rosin is obtained by solvent extraction of pine tree Perkins mixer Aft the ingredients have b h hstumps which have been in the ground for a number of 1y mixed they are than passed through a n to form a years tree h been cut down' A third source tile blanket. The tile blanket is formed in accordance of rosm acldsfim t a by'pmduct of Wood pulp. with methods well known in the art, generally between facture' Rosm. 1S .m approxlmatdy a cold roll maintained at a temperature of about 140- of 90% by weight acidic material and 10% neutral ma 220 F and a hot roll maintained at a temperature of terial. The characterrshcs of rosin are determined largely F Th {1 h d h h t by the acid fraction. Of the acid fraction, about 50% by about 240 3 e 16 i t en passe t mug a weight consists of abietic acid, levopimaric acid, and neoleast one Calender to fimsh forming the h t The Galen abietic acid. These three acids differ only in the posidef face r011 temperature may be malntamet at about tion of the conjugated system in the molecule. Another 1100-2000 Whlle the back T011 y be relatively C001, 20% by weight of the acid fraction is often made up of below about These T011 temperatures, however, two stereoisomers, dextropimaric and isodextropimaric y Vary- After Calendefing, the blanket is Cooled and acids. The balance of the rosin acid fraction comprises finally cut into tile of the desired size. Any finishing tetrahydroabietic acid which has no ethylenic unsaturaoperations such as coating the surface with a wax, lacquer, tion, dihydroabietic acid which contains one double bond, or other coating material may then be carried out. The and dehydroabietic acid, the unsaturation of which conm i th ready f i t ll ri on afloon sists of an aromatic ring- The following examples illustrate several embodiments Another usable rosin acid is that obtained from rosin of h i ti All parts are by weight unless th s by carrying out a polymerization at room temperature by wise Statei the action of alkyl or metal halides or inorganic acids. EXAMPLE 1 Rosin may be dissolved in a solvent such as petroleum ether and treated with concentrated sulfuric acidwith A Series Of Vinyl asbestos p i i s Were h HghIY cooling-for six hours. The resulting polymerized rosin blended at a temperature in the range of 280-320 F. is esentially a dimer in which the abietic acid molecule Tiles were made from each composition. Following is are joined together by a sharing of one of the double the list of ingredients in each series of tile:

Parts Ingredients Control A B O D E F G Asbestos Limestone. Titanium d xide Vinyl chloridevinyl acetate copolymer resin mixture Epoxidized soya oil Butyl benzyl phthalate Dicyandiamide,

Barium stearate- Zinc stearate Alpha methyl glucos Mr-lamina Abictic acid W.W. wood rosin bonds. This dipolymer, called dimerized rosin acid herein, is particularly suitable in the present invention.

All of the rosin acids suitable for use in the present Dymerex is 80% by weight rosin acid dimer, and 20% by weight monomeric rosin acids and neutral materials. Penros is dimerized wood rosin containing 14% unsaponiinvention are characterized by the presence on the molefiables. W. W. Wood rosin is a light colored wood rosin containing about 90% rosin acids and 10% neutral materials.

Specimens of tile made from each of the compositions listed above were tested as to whether or not the initial color was satisfactory or unsatisfactory, and as to the percent of moisture growth and the percent of moisture absorption. Following are the results:

Moisture Moisture Tile Initial Color Growth, Absorption,

Percent Percent 0. 31 2. 03 0. 05 1. 14 0. 09 1. 05 0. 09 1. 06 0. l. 09 0. 10 l. 01 0. 05 0. 88 0. 05 l. 07

EXAMPLE 2 A series of vinyl asbestos compositions were prepared. Following are the formulae:

Parts Ingredients Control H J K L Asbestos 200 200 200 200 200 Ground limestone, 40 mesh 570 570 570 570 570 Titanium dioxide 40 40 40 40 40 Vinyl chl0ride-vinyl acetate copolymer resin mixture Epoxidized soya oil Butyl benzyl phthalate Dicyandiamide, 70%..- Barium stearate Zine stearate Alpha methyl glucoside- Melamine Dimerized rosin (Penros).

Specimens of the above tile were tested as in Example 1 for satisfactory or unsatisfactory initial color, for moisture The unsatisfactory color in tile H and J was due to a pronounced pink appearance in the tile.

EXAMPLE 3 The following two vinyl asbestos compositions were prepared:

Parts Ingredients Control M Asbestos 200 200 Ground limestone, 40 me h 568 568 Titanium dioxide- 4O 40 Poly vinyl chloride) re 120 120 Epoxidized soya 0il 6. 6.2 Butyl benzyl phthalate 50. 8

Dicyandiamide, 70% Barium stearate.

Testing of specimens of the above tile .gave the following results:

Moisture Moisture Tile Initial Color Growth, Absorption,

Percent Percent Sat 2. 18 0. 44 Sat. 1. 36 0. 16

We claim:

1. A vinyl asbestos composition comprising a vinyl chloride resin, asbestos, and a stabilizing system com prising a stabilizing amount of about 0.1%2.5% by weight melamine and about 0.05%4% by weight rosin acid based on the weight of said composition.

2. A composition according to claim 1 wherein said vinyl chloride resin comprises a vinyl chloride-vinyl acetate copolymer.

3. A composition according to claim 1 wherein said melamine is present in an amount of about 0.4%-1% by weight.

4. A composition according to claim 1 wherein said rosin acid is present in an amount of about 0.2%-1.2% by weight.

5. A composition according to claim 1 wherein said rosin acid comprises wood rosin.

6. A composition according to claim 1 wherein said rosin acid comprises abietic acid.

7. A composition according to claim 1 wherein said rosin acid comprises dimerized rosin acid.

8. A vinyl asbestos composition comprising 3%-50% by weight asbestos fibers, 20%80% by weight granular inorganic filler, 8%30% by weight vinyl chloride resin binder, 0.2%l0% by weight plasticizer :for said vinyl chloride resin, 0.1%-2.5% by weight melamine, and 0.05 %4% by Weight of rosin acid.

p. 12728h relied on.

Chemical Abstracts, vol. 55, No. 14, July 10, 1961, p. 13919f.

Hercules: Wood Rosins and Stabilized Rosins, Bulletin of Hercules Powder Co., Bulletin No. 400-429C 4M 9-57 4871, pp. 3-6, 8 and 12 relied upon.

Chevassus et al.: The Stabilization of Polyvinyl Chloride, p. 149 relied on.

LEON J. BERCOVITZ, Primary Examiner.

F. MCKELVEY, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,314,906 April 18, 1967 George E. Bagley et a1.

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

In the heading to the printed specification, lines 4 to 7, for, "George E. Bagley, Lancaster County, Pa. (2425 Mayfair Drive, Lancaster, Pa. 17603) and William F. Goodyear, Jr. Lancaster County, Pa. (72 Barre Drive, Lancaster, Pa. 17601)" read George E. Bagley and William F. Goodyear, J13, both f Lancaster County, Pa. assignors to Armstrong Cork Company, Lancaster, Pa., a corporation of Pennsylvania column 3, line 32 for "in" read is Signed and sealed this 14th day of November 1967.

(SEAL) Attest:

EDWARD J BRENNER EDWARD M.FLETCHER,JR.

Commissioner of Patents Attesting Officer 

1. A VINYL ASBESTOS COMPOSITION COMPRISING A VINYL CHLORIDE RESIN, ASBESTOS, AND A STABILIZING SYSTEM COMPRISING A STABILIZING AMOUNT OF ABOUT 0.1%-2.5% BY WEIGHT MELAMINE AND ABOUT 0.05%-4% BY WEIGHT ROSIN ACID BASED ON THE WEIGHT OF SAID COMPOSITION. 